ok so just in case anybody reads this in the future and has a similar problem:
i ended up not being about to move the files back into udata.
what i COULD do was move the files into another folder in the same partition with no problem.
so i did that, deleted the udata folder and renamed the new folder. and it worked! my xbox is back up and running!!!
now to try on the 2nd one...
movak thank you very, very much for your help.
the drive is not failing...i'm not really sure why that happened but at least i found a way around it.
wasted the whole day but its working now so that wasn't a waste! i even played some burnout revenge to celebrate